Ichihara oversees the Cybergenic Research Institute as a Ministry of Defense scientist specializing in cybernetic enhancement technology. His primary objective involves procuring test subjects from the Special Security Force for experimental procedures, facing resistance from Chief Taki who prohibits using agents. When Raiden suffers life-threatening injuries battling communist terrorists, Ichihara intervenes. He provides Raiden with extensive cybernetic augmentation, transforming him into a powerful cyborg after confirming voluntary consent. This achievement fulfills Ichihara's ambition despite Taki's objections and establishes a functional relationship between the scientist and the enhanced agent. Ichihara later becomes entangled in the H-File political conspiracy, where corrupt officials plan nuclear waste dumping in Hokkaido. His knowledge makes him a critical witness and target. During the conspiracy's climax, he actively supports Raiden and surviving Special Security agents against attacks from corrupt forces and the psychic antagonist Lucifer, expressing visible satisfaction at Raiden's combat effectiveness. His involvement concludes when Lucifer, recovering in the laboratory's generator room, uses telekinesis to trigger an explosion in Ichihara's computer console, resulting in his death during the final confrontation. The character's narrative arc remains consistent across official media without significant deviations in alternate adaptations or spin-offs.